High-performance metal-organic framework-perovskite hybrid as an important component of the air-electrode for rechargeable Zn-Air battery

Constructing catalysts with a low overpotential for the oxygen evolution reaction (OER) is critical for the increased application of rechargeable Zn-air batteries. Herein, an in-situ cobalt extraction and simultaneous coordination growth strategy is adopted to develop an active and robust interface between nanostructural Co-metal-organic framework (Co-MOF) pillars and perovskite LaCoO_3-δ (LC). Moreover, the multi-active cobalt sites, including Co³⁺ in the LC and coordinatively unsaturated cobalt sites in the Co-MOF, could promote the deprotonation of oxygen adsorption intermediates and act as catalytic active centres. Therefore, the optimal sample exhibits excellent OER activity with a low overpotential of 330 mV. Notably, the Zn-air battery with Co-MOF/LC-0.5 as the OER catalyst exhibits a low charge potential of 2.03 V and excellent cycling stability. This work illustrates efficient electrochemical catalysts based on perovskites with low overpotentials that are prepared by an in-situ growth strategy, and have great potential in rechargeable Zn-air batteries.